#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e5+100;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
LL a[maxn],b[maxn],sum[maxn];
int main(void)
{
  cin.tie(0);std::ios::sync_with_stdio(false);
  LL n,q,k;cin>>n>>q>>k;
  for(LL i=1;i<=n;i++) cin>>a[i];
  for(LL i=1;i<n;i++){
    sum[i]=sum[i-1]+(a[i+1]-a[i-1]-2);
  }
  while(q--){
    LL l,r;cin>>l>>r;
    if(l==r){
        cout<<k-1<<"\n";
        continue;
    }
    LL ans=0;
    if(r-l>1) ans+=sum[r-1]-sum[l];
    ans+=(k-a[r-1]-1);
    ans+=(a[l+1]-2);
    cout<<ans<<"\n";
  }
return 0;
}
